Elbow pain may arise from any of the several structures making up the elbow or from structures around the elbow. It is important to understand the anatomy of the elbow in order to identify possible causes of elbow pain. The elbow is a complex joint that is responsible for movement in more than one axis. It allows for motion of the forearm and serves as a major site of attachment for the muscle tendons of the wrist and fingers. Given that the arms are the most active parts of the human body and often undergoing significant strain and wear-and-tear, elbow pain is not an uncommon occurrence.
The elbow is the area between the upper and lower arm (forearm). It is a joint that is made of three bones – humerus (upper arm bone) and radius and ulnar (forearm bones). There three points of articulation between the humerus and radius, humerus and ulnar and the radius and ulnar. The articulating surfaces of these bones is covered with cartilage to prevent erosion of the bone and serve as a shock absorber.. The most prominent features of the elbow is the protrusion at the back (posterior) which is formed by the olecranon process of the ulnar and the pit of the elbow in the front (anterior) known as the cubital fossa. A bony protrusion on the outer side of the humerus is known as the lateral epicondyle while an inner side protrusion is referred to as the medial epicondyle.
Joints and Muscles
The articulation between the humerus and radius-ulna is a hinge joint that allows for flexion and extension (bending and straightening) of the forearm. The more of a ball-and-socket type joint between the radius and ulna allows for an inner and outer twisting (pronation and supination) of the forearm. The synovial membrane lining these joints is extensive and is separated from the surrounding capsule by masses of fat. Many muscles are responsible for the facilitating and stabilizing movement at the elbow joint but the more important muscles to note include the biceps brachii, triceps brachii, brachialis, brachioradialis, pronator teres and extensor carpi radialis brevis.
There are several other muscles, not only those that bend, straighten or twist at the elbow joint, which have attachments in or near the elbow. This is marked by two important protrusions on the side of the elbow – the inner protrusion (medial epicondyle) and the outer protrusion (lateral epicondyle). The muscles that bend the wrist and fingers (wrist flexors) come together to attach as a single tendon at the medial epicondyle. Those muscles that straighten the wrist and fingers (wrist extensors) come together as a single tendon to attach at the lateral epicondyle. Other important tendons include that of the biceps and triceps muscles which allow for forceful bending and straightening of the arm.
Ligaments and Nerves
The three most important ligaments in the elbow are the medial and lateral collateral ligaments and the annular ligament. The collateral ligaments help to tightly hold the ulnar to the humerus while the annular ligament holds the radius tightly against the ulna. Important nerves that run in and around the area include the ulnar, median and radial nerves.
Other Symptoms with Elbow Pain
Elbow pain is a symptom indicative of some underlying disease of the elbow joint or nearby structures. The pain may be persistent or episodic and can be triggered or exacerbated by movement. Pain with certain movement of the forearm may help to indicate a possible cause or at least the structures involved from which the pain is arising. The pain may extend up to the shoulder and down the forearm to the hands and fingers. Tenderness may be present upon applying pressure to the area.
The mobility of the elbow joint may be reduced either limited by pain upon movement, as a result of muscle weakness, swollen joint or other disease mechanism within the affected area. Redness, swelling and warmth of the area is an indication of acute inflammation and more frequently seen with infectious causes. A lump in the area may be due to an abscess, tumor, bleeding within the joint (hemarthrosis) or even swollen lymph nodes. Other abnormal sensations like numbness and tingling may accompany the pain at the elbow or involved other parts of the arm. Paralysis and significant joint deformity are serious symptoms that require immediate medical attention.
Causes of Elbow Pain
As with any joint, pain may be a result of inflammation of the joint itself or surrounding structures. More common causes of elbow pain include overuse and sporting injuries. The most notable conditions that causing elbow pain include :
- Tendonitis is the inflammation of the muscle tendon that attaches the muscles to bones. It can become inflamed from strain, overuse, injury and other causes like infections.
- Tennis elbow or lateral epicondylitis is the inflammation of the tendons that connect to the outer bony protrusion of the elbow (lateral epicondyle). These are the tendons of the muscles responsible for extension of the wrist and fingers.
- Golfer’s elbow or medial epicondylitis is the inflammation of the the tendons that connect to the inner bony protrusion of the elbow (medial epicondyle). These are the tendons of the muscles responsible for flexion of the wrist and fingers.
- Bursitis is the inflammation of fluid filled pouches in the elbow that reduce friction between two body surfaces. The most significant type of bursitis in the elbow joint that may cause pain is olecranon bursitis. This bursa lies at the tip of the elbow and inflammation may arise from trauma to the area or with diseases like rheumatoid arthritis.
- Arthritis is the inflammation of the joint lining of even articular cartilage. There are various different types of arthritis including rheumatoid arthritis, osteoarthritis and septic arthritis (infection). Hemarthrosis is bleeding within a joint that may arise with blood vessel injury and cancers but may also occur repeatedly in osteoarthritis.
- Sprains are inflammation of a ligament or the ligaments in the elbow associated with stretching or tearing.
- Fractures are usually associated with significant trauma to the humerus, radius or ulna. Fragments of bone may remain within the elbow joint causing ongoing pain for months or even years afterwards.
- Dislocation may occur when any of the three bones of the elbow joint shifts out of its position of articulation. This separation may be partial (subluxation) or complete. It arises with severe injury to the elbow like with hard falls. The dislocation may occur on its own (simple), in conjunction with injuries to the bone and ligaments (complex) or even involve blood vessels and nerves (severe). A common type of dislocation that occurs in very young children is nursemaid elbow where there is partial dislocation of the radial head. It is associated with forceful pulling of a child by the arm or swinging by the arms.
- Thrower’s elbow is a bone related injury in children associated with regular and forceful throwing as in baseball pitching. It more commonly associated with medial apophysitis (little leaguer’s elbow) and less frequently due to osteochondritis dissecans.
- Bone cancers do not commonly affect the elbow joint as often as it does the hip and shoulder joints. It may be primary where the tumor originates at the site or secondary (metastatic) where it is spread from distant sites.
- Other bone diseases may include osteoporosis, osteomalacia (adults), rickets (children) and osteomyelitis.
- Neuritis is inflammation of the nerves running through the elbow or innervating structures in the elbow. It is a common cause of pain and includes conditions such as cubital tunnel syndrome (ulnar nerve injury) and radial tunnel syndrome (radial nerve injury).
- Referred pain is most notably caused by irritation or compression of the cervical nerve roots (pinched neck nerves).
- Other systemic conditions apart from causes such as rheumatoid arthritis which may also cause elbow pain includes :
- Acute rheumatic fever